Indexing architecture including an optical fiber cable fan-out arrangement

ABSTRACT

The present disclosure relates to indexing cables for use in building fiber optic networks using an indexing architecture. In certain examples, fan-out structures are used. Certain types of indexing cables have one or more branch cable sections at each end. Certain types of indexing cables have multiple interface cable sections at one or both ends.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.16/330,958, filed on Mar. 6, 2019, now U.S. Pat. No. 10,690,875, whichis a National Stage Application of PCT/EP2017/072133, filed on Sep. 4,2017, which claims the benefit of U.S. Patent Application Ser. No.62/383,965, filed on Sep. 6, 2016, the disclosures of which areincorporated herein by reference in their entireties. To the extentappropriate, a claim of priority is made to each of the above disclosedapplications.

TECHNICAL FIELD

The present disclosure relates generally to equipment for fiber opticcommunications networks. More particularly, the present disclosurerelates to fiber optic networks including indexing architectures andfan-outs.

BACKGROUND

Optical networks are becoming increasingly prevalent in part becauseservice providers want to deliver high bandwidth communicationcapabilities to customers. As the demand for optical networks increases,there is a need to extend fiber optic networks closer to the edge (i.e.,closer to subscriber locations). In this regard, there is a need forcost-effective architectures for extending fiber optic networks. Oneexample of a cost-effective architecture is an indexing architecture.Example indexing architectures are disclosed by PCT Int'l PublicationNo. WO 2014/190281.

SUMMARY

Aspects of the present disclosure relate to an indexing cable extendingbetween a first end and a second end. The indexing cable includes aplurality of optical fibers. The indexing cable also includes a firstinterface cable section disposed at the first end of the indexing cable;a first branch cable section disposed at the first end of the indexingcable; a second interface cable section disposed at the second end ofthe indexing cable; and a second branch cable section disposed at thesecond end of the indexing cable. The first branch cable sectionincludes fewer of the optical fibers than the first interface cablesection. The second branch cable section includes fewer of the opticalfibers than the second interface cable section.

In certain implementations, the first interface cable is one of aplurality of first interface cables.

In certain implementations, the first branch cable is one of a pluralityof first branch cables.

In accordance with some aspects of the disclosure an indexing componentincluding a main cable section including a plurality of optical lines.The optical lines extend between first and second ends. The first endsof the optical lines are separated into a first branch set and a firstinterface set. The second ends of the optical lines are separated into asecond branch set and a second interface set. The first branch set hasfewer optical lines than the first interface set and the second branchset has fewer optical lines than the second interface set. The opticallines of the first branch set are different from the optical lines ofthe second branch set. The second interface set includes the opticallines of the first branch set. The first interface set includes theoptical lines of the second branch set. A first interface multi-fiberconnector has a plurality of sequential positions. The first interfacemulti-fiber connector terminates the first interface set so that theoptical lines of the first interface set are indexed at the sequentialfiber positions of the first interface multi-fiber connector. A secondinterface multi-fiber connector has a plurality of sequential positions.The second interface multi-fiber connector terminates the secondinterface set so that the optical lines of the second interface set areindexed at the sequential fiber positions of the second interfacemulti-fiber connector. A first branch multi-fiber connector terminatesthe first branch set. A second branch multi-fiber connector terminatesthe second branch set.

In certain implementations, the main cable section extends between afirst end and a second end. The first interface set and the first branchset are separated from each other at a first fanout arrangement disposedat the first end of the main cable section. The second interface set andthe second branch set are separated from each other at a second fanoutarrangement disposed at the second end of the main cable section.

In certain implementations, the first interface set of optical linesform a first interface cable section that extends between the firstinterface multi-fiber connector and the first fanout arrangement. Thesecond interface set of optical lines form a second interface cablesection that extends between the second interface multi-fiber connectorand the second fanout arrangement.

In certain implementations, at least one of the fanout arrangementsincludes a plurality of fanouts. In certain implementations, at leastone of the fanout arrangements includes a single fanout.

In certain implementations, the first interface connector is one of aplurality of first interface connectors and the first interface cablesection is one of a plurality of first interface cable sectionsextending from the first fanout arrangement to a respective one of thefirst interface connectors.

In some implementations, the first branch set of optical fibers includesa single optical fiber. In other implementations, the first branch setof optical fibers includes a plurality of optical fibers.

In certain examples, the first branch multi-fiber connector has a numberof sequential positions, and the first branch set includes a number ofthe optical lines that is less than the number of sequential positionsof the first branch multi-fiber connector.

In certain examples, a number of sequential positions of the firstbranch multi-fiber connector is less than the number of the sequentialpositions of the first interface multi-fiber connector.

In certain examples, the second branch multi-fiber connector has anumber of sequential positions and the second branch set includes anumber of the optical lines that is less than the number of sequentialpositions of the second branch multi-fiber connector.

In certain implementations, each optical line is formed by a singlefiber.

In certain implementations, the first and second interface multi-fiberconnectors are ruggedized.

In certain implementations, the first and second branch multi-fiberconnectors are ruggedized.

In certain implementations, the main cable section has a sufficientnumber of optical lines to fill all of the sequential positions of thefirst interface connector and at least one sequential position of thefirst branch connector.

Other aspects of the present disclosure relate to an indexing cable. Theindexing cable includes a main cable section extending between a firstfanout and a second fanout. The main cable section includes opticalfibers. A first interface cable section extends outwardly from the firstfanout by a first interface length that is less than a length of themain cable section. The first interface cable section is terminated by afirst interface multi-fiber connector defining a plurality of sequentialpositions. A second interface cable section extends outwardly from thesecond fanout by a second interface length that is less than the lengthof the main cable section. The second interface cable section isterminated by a second interface multi-fiber connector defining aplurality of sequential positions. A first branch cable section extendsoutwardly from the first fanout by a first branch length that is lessthan the length of the main cable section. The first branch cablesection is terminated by a first branch connector. One of the opticalfibers extends between the first branch connector and the secondinterface multi-fiber connector. A second branch cable section extendsoutwardly from the second fanout by a second branch length that is lessthan the length of the main cable section. The second branch cablesection is terminated by a second branch connector. Another of theoptical fibers extends between the second branch connector and the firstinterface multi-fiber connector.

In certain implementations, some of the optical fibers are indexedbetween the first and second interface multi-fiber connectors.

In certain implementations, the first branch connector is a multi-fiberconnector.

In certain implementations, the first branch connector receives firstends of a plurality of the optical fibers.

In certain implementations, the first branch connector has a number ofsequential fiber positions that equals a number of sequential fiberpositions of the first interface multi-fiber connector.

In certain implementations, the first branch connector has a number ofsequential fiber positions that is less than a number of sequentialfiber positions of the first interface multi-fiber connector.

In certain implementations, the first interface cable section is one ofa plurality of first interface cable sections extending outwardly fromthe first fanout. Each first interface cable section is terminated by arespective first interface multi-fiber connector defining a plurality ofsequential positions. The second interface cable section is one of aplurality of second interface cable sections extending outwardly fromthe second fanout. Each second interface cable section is terminated bya respective second interface multi-fiber connector defining a pluralityof sequential positions.

In certain examples, the first branch connector and the respectivemulti-fiber connectors of the first interface cable sections cooperateto define sequential first interface positions. The second branchconnector and the respective multi-fiber connectors of the secondinterface cable sections cooperate to define sequential second interfacepositions. The optical fibers are indexed between the first interfacepositions and the second interface positions.

In certain examples, one of the first interface cable sections includesa different number of optical fibers than another of the first interfacecable sections.

In certain implementations, the first branch cable section is one of aplurality of first branch cable sections extending outwardly from thefirst fanout. Each first branch cable section being terminated by arespective first branch connector. The second branch cable section isone of a plurality of second branch cable sections extending outwardlyfrom the second fanout. Each second branch cable section is terminatedby a respective second branch connector.

In certain examples, the first interface cable section is one of aplurality of first interface cable sections extending outwardly from thefirst fanout. Each first interface cable section is terminated by arespective first interface multi-fiber connector defining a plurality ofsequential positions. The second interface cable section is one of aplurality of second interface cable sections extending outwardly fromthe second fanout. Each second interface cable section is terminated bya respective second interface multi-fiber connector defining a pluralityof sequential positions.

In certain examples, the respective multi-fiber connectors of the firstinterface cable sections cooperate to define sequential first interfacepositions. The respective multi-fiber connectors of the second interfacecable sections cooperate to define sequential second interfacepositions. The optical fibers are indexed between the first interfacepositions and the second interface positions.

In an example, one of the first interface cable sections includes adifferent number of optical fibers than another of the first interfacecable sections.

In certain examples, one of the first branch cable sections includes adifferent number of optical fibers than another of the first branchcable sections.

A variety of additional aspects will be set forth in the descriptionthat follows. These aspects can relate to individual features and tocombinations of features. It is to be understood that both the forgoinggeneral description and the following detailed description are exemplaryand explanatory only and are not restrictive of the broad concepts uponwhich the examples disclosed herein are based.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of an indexing cable including aninterface cable section and a branch cable section at a first end of thecable and an interface cable section and a branch cable section at asecond end of the cable in accordance with the principles of the presentdisclosure;

FIG. 2 shows the indexing cable of FIG. 1 daisy-chained to another suchindexing cable in accordance with the principles of the presentdisclosure;

FIG. 3 is a schematic diagram of another indexing cable including branchconnectors that have fewer fiber positions than the interfaceconnectors;

FIG. 4A is a schematic diagram showing optical equipment opticallycoupled to the branch cable sections of the indexing cable of FIG. 3;

FIG. 4B is a schematic diagram showing other optical equipment opticallycoupled to the branch cable sections of the indexing cable of FIG. 3;

FIG. 5 is a schematic diagram of an example indexing cable havingmultiple interface cable sections;

FIG. 6 is a schematic diagram of an example indexing cable havingmultiple branch cable sections;

FIG. 7 is a schematic diagram of an example indexing cable havingmultiple fanouts at each fanout arrangement; and

FIG. 8 is a schematic diagram of an example indexing cable configured toenable signals to be input onto the indexing cable through both a firstinterface connector and a first branch connector.

DETAILED DESCRIPTION

Reference will now be made in detail to exemplary aspects of the presentdisclosure that are illustrated in the accompanying drawings. Whereverpossible, the same reference numbers will be used throughout thedrawings to refer to the same or like structure.

Aspects of the present disclosure relate to components for supportingindexing architectures. In certain examples, the components can includeindexing cables. In certain examples, the indexing architectures caninclude forward and reverse indexing. It will be appreciated thatexamples of forward and reverse indexing architectures and of systemswhere multiple indexing components are daisy-chained together aredisclosed by PCT Int'l Publication No. WO 2014/190281, which is herebyincorporated by reference in its entirety.

FIG. 1 illustrates an indexing cable 100 terminated at opposite ends byinterface connectors 104, 106 and branch connectors 108, 110. Theindexing cable 100 includes a plurality of optical fibers 102 thatextend along a main cable section 101. Multiple indexing cables can bedaisy-chained together to form a fiber path (see FIG. 2). Fiber linesare progressively branched from locations along the fiber path. As thefiber lines are branched, the remaining fiber lines are progressivelyindexed along the chain in at least a first indexing direction I₁. Incertain examples, the fibers also are progressively indexed along thechain in a second indexing direction I₂. Each fiber line includes one ormore optical fibers optically coupled together to extend along the fiberpath.

As shown in FIG. 1, one or more of the optical fibers 102 of each cable100 branch out from the main cable section 101 at the first and secondends of the cable 100. At each end of the indexing cable 100, the branchfibers—called a branch set—are connectorized separately from thenon-branch fibers—called an interface set.

Each of the interface connectors 104, 106 defines a plurality ofsequential fiber positions for receiving fibers of the interface set.First ends of at least some fibers 102 of the indexing cable 100disposed at the sequential fiber positions of the first interfaceconnector 104. These fibers include fibers that do not branch and fibersthat branch at the second end. The second end of a branch one of thesefibers is terminated at a branch connector 110 at the second end of thecable 100. The second end of the first non-branch one of these fibers(i.e., the non-branch fiber having the first end sequentially closest tothe first sequential position at the first interface connector 104) isindexed to the first sequential position at the second interfaceconnector 106 at the second end of the cable 100.

Indexing cables are daisy-chained together by optically coupling thesecond interface connector 106 of one cable 100A and the first interfaceconnector 104 of another cable 100B (see FIG. 2). Fiber lines extendfrom the first interface connector 104 of the first cable 100A towardsthe second interface connector 108 of the last cable 100B. The indexingcables 100A, 100B along the fiber path will follow a predeterminedschema so that each fiber line is branched when it reaches apredetermined sequential fiber position of one of the interfaceconnectors 104, 106. Each branch fiber line can be routed from thebranch location to a subscriber or elsewhere in the network (e.g.,subsequent to the cable chaining).

In certain examples, one or more fibers 102 of a cable 100 can branchfrom the main cable section 101 at the first end of the cable 100 (seeFIG. 1). The branch fibers at the first end of the cable 100 areconnectorized separately from the non-branch fibers at the first end.

Second ends of some fibers 102 of the indexing cable 100 are disposed atthe sequential fiber positions of the second interface connector 106.These fibers include fibers that do not branch and fibers that branch atthe first end. The first end of a branch one of these fibers isterminated at a branch connector 108 at the first end of the cable 100.Typically, the second end of the branch one(s) of these fibers is/areterminated at the last active sequential position(s) at the secondinterface connector 106. In certain examples, the last active sequentialfiber position need not be the last sequential fiber position of theconnector. For example, if an interface connector 104, 106 has Nsequential fiber positions, then the interface connector may receive N−xfibers wherein x is any integer between 0 and (N−1). In such an example,the last active sequential fiber position may be position N−x.

Referring still to FIG. 1, the example indexing cable 100 shown includesa main cable section 101 extending between a first fanout arrangement111 and a second fanout arrangement 112. The main cable section 101includes optical fibers 102. A first interface cable section 103 extendsoutwardly from the first fanout arrangement 111 by a first interfacelength that is less than a length of the main cable section 101. Thefirst interface cable section 103 is terminated by the first interfaceconnector 104. A second interface cable section 105 extends outwardlyfrom the second fanout arrangement 112 by a second interface length thatis less than the length of the main cable section 101. The secondinterface cable section 105 is terminated by the second interfaceconnector 106.

As the term is used herein, a fanout arrangement 111, 112 refers to oneor more fanouts that transitions the optical fibers from the main cablesection 101 to one of the cable sections 103, 105, 107, 109. A fanoutrefers to a structure that separates or groups optical fibers. In someexamples, a fanout can include a rigid body that holds the opticalfibers. In other examples, the fanout can include a flexible body thatencloses the optical fibers. In still other examples, the fanout canenclose spliced optical fibers. Examples of suitable fanouts aredisclosed in U.S. Provisional Application No. 62/375,404, filed Aug. 15,2016, and titled “Indexing Architecture Including a Fan-outArrangement,” the disclosure of which is hereby incorporated herein byreference.

In still other implementations, the cable 100 does not include fanoutarrangements 111, 112. Rather, the fibers 102 of the main cable section101 can be glued together while the fibers 102 of the interface cablesections and branch cable sections are not glued together. For example,the optical fibers 102 of the main cable section 101 can be ribbonizedand split into two ribbonized groups without a structure disposed at thesplit.

Still referring to FIG. 1, a first branch cable section 107 extendsoutwardly from the first fanout arrangement 111 by a first branch lengththat is less than the length of the main cable section 101. The firstbranch cable section 107 is terminated by a first branch connector 108.One of the optical fibers 102 extends between the first branch connector108 and the second interface multi-fiber connector 106.

A second branch cable section 109 extends outwardly from the secondfanout arrangement 112 by a second branch length that is less than thelength of the main cable section 101. The second branch cable section109 is terminated by a second branch connector 110. Another of theoptical fibers 102 extends between the second branch connector 110 andthe first interface multi-fiber connector 104.

The first fanout arrangement 111 combines the optical fibers 102 of thefirst interface cable section 103 and the optical fibers 102 of thefirst branch cable section 107 onto the main cable section 101. Thesecond fanout arrangement 112 combines the optical fibers 102 of thesecond interface cable section 105 and the optical fibers 102 of thesecond branch cable section 109 onto the main cable section 101.

The optical fibers 102 that extend along the first interface cablesection 103 from the first interface multi-fiber connector 104 arerouted through the first fanout arrangement 111, along the main cable101, to the second fanout arrangement 112. These optical fibers 102 areseparated at the second fanout arrangement 112 into branch fibers andnon-branch fibers. The branch fibers are routed through the secondbranch cable section 109 and the non-branch fibers are routed throughthe second interface cable section 105. In particular, at least theoptical fiber 102 that corresponds to a first sequential fiber positionat the first interface multi-fiber connector 104 is routed to the secondbranch cable section 109. The interface fibers are indexed along thesequential fiber positions of the second interface multi-fiber connector106.

The optical fibers 102 that extend along the second interface cablesection 105 from the second interface multi-fiber connector 106 arerouted through the second fanout arrangement 112, along the main cable101, to the first fanout arrangement 111. These optical fibers 102 areseparated at the first fanout 111 into branch fibers and non-branchfibers. The branch fibers are routed through the first branch cablesection 107 and the non-branch fibers are routed through the firstinterface cable section 103. In particular, at least the optical fiber102 that corresponds to a last active sequential fiber position at thesecond interface multi-fiber connector 106 is routed to the first branchcable section 107. The non-branch fibers are indexed along thesequential fiber positions of the first interface multi-fiber connector104.

In certain implementations, the first branch connector 108 is amulti-fiber connector. In certain examples, the first and second branchconnectors 108, 110 are multi-fiber connectors. In certain examples, thefirst and second branch connectors 108, 110 are hardened connectors. Incertain examples, the first and second branch connectors 108, 110 arehardened multi-fiber connectors.

In some implementations, the first branch connector 108 has a number ofsequential fiber positions that is equal to a number of sequential fiberpositions of the first interface multi-fiber connector 104 (e.g., seeFIG. 1). In other implementations, the first branch connector 108 has anumber of sequential fiber positions that is less than a number ofsequential fiber positions of the first interface multi-fiber connector104 (e.g., see FIG. 3).

In certain implementations, the first branch connector 108 receives aplurality of the optical fibers 102. In certain implementations, thefirst branch connector 108 receives a fewer number of the optical fibers102 than the first non-branch multi-fiber connector 104 (e.g., see FIG.1).

In certain implementations, the second branch connector 110 receives aplurality of the optical fibers 102. In certain implementations, thesecond branch connector 110 receives a fewer number of the opticalfibers 102 than the second interface multi-fiber connector 106. Incertain examples, the second branch connector 110 receives a commonnumber of optical fibers as the first branch connector 108.

As shown in FIG. 2, two or more indexing cables 100A, 100B can bedaisy-chained together to from an extended indexing cable 115. Thebranch cable sections 103A, 109A, 103B, 109B allow optical equipment tobe connected to various locations along the length of the extendedindexing cable 115.

In certain implementations, the number of cables 100A, 100B that can bedaisy-chained together is equal to the total number of optical fibers102 of the main cable sections 101 divided by the greater of the numberof optical fibers 102 branched at the first branch cable sections 107A,107B or the number of optical fibers 102 branched at the second branchcable sections 109A, 109B. In certain examples, the number of fibersdropped at the first branch cable sections 107A, 107B is equal to thenumber of fibers dropped at the second branch cable sections 109A, 109B.

In the example shown, the first indexing cable 100A is identical to thesecond indexing cable 100B. In other examples, the indexing cables 100Ahave a common number of optical fibers at the interface multi-fiberconnectors 104, 106.

A first interface multi-fiber connector 104B of the second cable 100B isconnected to the second interface multi-fiber connector 106A of thefirst cable 100A. Because the optical fibers 102 are indexed between thefirst and second interface multi-fiber connectors 104, 106 of each cable100, the active fiber positions of the second interface multi-fiberconnector 106A match the active fiber positions of the first interfacemulti-fiber connector 104B.

As shown in FIG. 3, the branch connectors of an indexing cable can havea different number of sequential fiber positions than the interfacemulti-fiber connectors. For example, the indexing cable 100′ shown inFIG. 3 has interface multi-fiber connectors 104, 106 with twelvesequential fiber positions each; the branch connectors 108′, 110′ of theindexing cable 100′, however, have four sequential fiber positions each.In other examples, however, the interface multi-fiber connectors 104,106 and the branch connectors 108′, 110′ can have any desired numbers ofsequential fiber positions. Using connectors having fewer fiberpositions for branch connectors 108′, 110′ as compared to interfaceconnectors 104, 106 can reduce the cost of manufacturing the cable 100′and/or reduce the cost of manufacturing equipment to be connected to thecable 100′.

For each branch connector 108′, 110′ having N sequential fiberpositions, the respective branch cable sections 107, 109 can includeanywhere between 1 and N optical fibers 102. In the example shown inFIG. 3, the first branch cable section 107 includes three optical fibers102 and the branch connector 108′ includes four sequential fiberpositions. In certain examples, if there are fewer optical fibers 102 inthe branch cable section 107, 109 than sequential fiber positions at thecorresponding branch connector 108′, 110′, then the optical fibers 102of the branch cable section 107, 109 may be indexed at the sequentialfiber positions of the branch connectors 108′, 110′.

Referring now to FIGS. 4A and 4B, subscribers or optical equipment canbe coupled to the optical network via the branch fibers of indexingcables 100, 100A, 100B, 100′. In some implementations, a distributioncable can be coupled to one or more branch fibers of the indexing cable100, 100A, 100B, 100′ to carry the optical signals of the branch fiberline from the indexing cables to the subscribers.

For example, FIG. 4A illustrates a piece of optical equipment 130 (e.g.,a drop terminal, a splitter terminal, a multiplexing terminal, etc.)coupled to the second branch cable section 109 of the indexing cable100′. In other implementations, the optical equipment 130 could becoupled to the branch cable section 107. In still other implementations,other types of optical equipment 140, 150, 160, 170 could be coupled tothe branch cable section 109. In still yet other implementations, any ofthe pieces of optical equipment 130, 140, 150, 160, 170 can be coupledto any or all of the branch cable sections.

The optical equipment 130 includes a body 131 defining one or moreoutput ports 132. Optical lines 135 optically couple the output ports132 to one or more input connectors 134. Each input connector 134 isconfigured to be optically coupled to one of the branch connectors 108′,110′ of the indexing cable 100′.

In some implementations, the optical equipment 130 includes a singleinput connector 134 terminating a stub cable that extends out from thebody 131 (see FIG. 4A). In other implementations, the optical equipment130 includes a single input connector 134 disposed on/in the body 131.In still other implementations, two or more input connectors 134 canterminate stub cables and/or be located on/in the body 131.

In some implementations, the output ports 132 of the optical equipment130 are single-fiber output ports. In other implementations, the outputports 132 of the optical equipment 130 are multi-fiber output ports. Instill other implementations, the output ports 132 of the opticalequipment 130 are a mixture of single-fiber output ports and multi-fiberoutput ports.

In some implementations, each of the output ports 132 of the opticalequipment 130 is optically coupled to one of the branch fibers in apoint-to-point connection. In other words, the optical signals carriedover the branch fiber are not split between the indexing cable 100,100A, 100B, 100′ and the output port 132. In other implementations,however, one or more output port 132 could receive split (e.g., powersplit, wavelength split, etc.) optical signals from the branch fibers.

For example, another type of optical equipment 150 is shown opticallycoupled to the first branch cable section 107. In other implementations,the optical equipment 150 could be coupled to the branch cable section109. In still other implementations, other types of optical equipment130, 160, 170 could be coupled to the branch cable section 107.

The optical equipment 150 includes a housing 152 that has more outputlines than input lines. For example, the housing 152 can hold a splitter153 (e.g., power splitter, wave division multiplexer, or other opticalequipment to split an optical signal). In certain examples,connectorized pigtails extend from the splitter 153 to interior ports ofthe outputs 154. In the example shown, the optical equipment 150includes a single input fiber 151 that feeds the splitter 153. In otherexamples, the splitter 153 may receive multiple inputs. In someexamples, the input fiber 151 is a connectorized stub cable extendingfrom the housing 152. In other examples, the input fiber 151 is aseparate cable. In an example, the separate cable is connectorized atboth ends.

In certain implementations, a fanout structure 140 can be opticallycoupled to one or more of the branch cable sections 107, 109 of theindexing cable 100. The fanout structure 140 is configured to transitiona grouping of branch fiber lines to separate fiber lines. For example,FIG. 4A shows an example fanout structure 140 having a multi-fiberconnector 142 that mates with the branch connector 108, 110 of theindexing cable. In some examples, the multi-fiber connector 142 iscarried by the housing 140. In other examples, the multi-fiber connector142 terminates a multi-fiber stub cable 141.

Within the fanout structure 140, optical fibers are routed from themulti-fiber connector 142 to different outputs. For example, in someimplementations, pigtails 143 may extend from the fanout structure 140and terminate at single-fiber connectors 144. In other implementations,the outputs may include ports disposed at the fanout structure 140.

For example, in FIG. 4A, a fanout structure 140 is optically coupled tothe first branch cable section 107 at which four optical lines arebranched. The fanout structure separates the four optical lines intofour outputs. In other examples, however, the fanout structure 140 canseparate the optical fibers into multiple multi-fiber outputs (e.g.,duplex fiber outputs). In the example shown, three of the outputs 143are single fibers terminated by single-fiber connectors 144 ready to beconnected to subscribers or other equipment. The fourth output opticallycouples to the input 151 of the splitter terminal 150.

In FIG. 4B, other types of optical equipment 160, 170 are shown coupledto the branch cable sections 107, 109. For example, a terminal 160 caninclude a multi-fiber input 162 (e.g., connectorized stub, connectorizedport, gland for multi-fiber cable, etc.). One or more of the inputfibers can be routed to a splitter 163 (e.g., a power splitter, a wavedivision multiplexer, etc.), from which the signals are carried tomultiple output ports 164. One or more other input fibers can be routeddirectly to output ports 166 to provide a point-to-point connection atthe terminal 160. Accordingly, the same terminal 160 can provideconnections for both split signals and unsplit signals.

Another example terminal 170 also is shown in FIG. 4B. The exampleterminal 170, which is shown coupled to the branch cable section 107,includes a single-fiber input 172. The single-fiber input 172 may feed asplitter (e.g., a power splitter, a wave division multiplexer, etc.)from which the signals are carried to multiple outputs 174. In certainexamples, each of the branch fibers 107 can be coupled to a differentterminal 170. In other examples, however, any optical equipment can becoupled to the branch fibers 107.

Referring to FIG. 5, certain types of indexing cables 200 includemultiple interface cable sections 203A, 203B, 205A, 205B extendingoutwardly from at least one of the fanout arrangements 211, 212. Eachinterface cable section 203A, 203B, 205A, 205B is terminated by arespective interface multi-fiber connector 204A, 204B, 206A, 206Bdefining a plurality of sequential positions.

In some implementations, the number of first interface cable sections203A, 203B is equal to the number of second interface cable sections205A, 205B. In other implementations, the total number of fibers 202 offirst interface cable sections is equal to the total number of fibers202 of the second interface cable sections while the number of firstinterface cable sections is different than the number of secondinterface cable sections. In an example, an indexing cable may have asingle first interface cable section and multiple second interface cablesections. In another example, an indexing cable may have multiple firstinterface cable section and a single second interface cable sections. Inanother example, an indexing cable may have two (or any desired number)first interface cable section and three (or any desired number) secondinterface cable sections.

The respective multi-fiber connectors 204A, 204B of the first interfacecable sections 203A, 203B cooperate to define a total number ofsequential first interface positions P1. If at least one of the fibers202 drops from the cable 200 at the first end of the cable 200, then thetotal number of fibers 202 received at the first interface cablesections 203A, 203B is less than the total number of sequential firstinterface positions P1. The respective multi-fiber connectors 206A, 206Bof the second interface cable sections 205A, 205B cooperate to define atotal number of sequential second interface positions P2. If at leastone of the fibers 202 drops from the cable 200 at the first end of thecable 200, then the total number of fibers 202 received at the secondinterface cable sections 205A, 205B is less than the total number ofsequential second interface positions P2.

In some implementations, when the optical fibers 202 are indexed at thefirst interface multi-fiber connectors 204A, 204B, the optical fibers202 are along the total number of sequential first interface positionsP1. Accordingly, depending on the number of optical fibers 202 beingdropped at the branch cable section 207 and the number of fiberpositions at each first interface multi-fiber connector 204A, 204B, one(or more) of the first interface multi-fiber connectors 204A receivesoptical fibers 202 at all of the sequential fiber positions of the firstinterface multi-fiber connector 204A and one (or more) of the firstinterface multi-fiber connectors 204B receives fewer optical fibers 202than it has sequential fiber positions. In other implementations, thefibers 202 can be separately indexed at each first interface multi-fiberconnector 204A, 204B so that each first interface multi-fiber connector204A, 204B receives fewer fibers 202 than it has sequential fiberpositions.

In some implementations, when the optical fibers 202 are indexed at thesecond interface multi-fiber connectors 206A, 206B, the optical fibers202 are indexed along the total number of sequential second interfacepositions P2. Accordingly, depending on the number of optical fibers 202being dropped at the branch cable section 209 and the number of fiberpositions at each second interface multi-fiber connector 206A, 206B, one(or more) of the second interface multi-fiber connectors 206A receivesoptical fibers 202 at all of the sequential fiber positions of thesecond interface multi-fiber connector 204A and one (or more) of thefirst interface multi-fiber connectors 204B receives fewer opticalfibers 202 than it has sequential fiber positions. In otherimplementations, the fibers 202 can be separately indexed at each secondinterface multi-fiber connector 206A, 206B so that each second interfacemulti-fiber connector 206A, 206B receives fewer fibers 202 than it hassequential fiber positions.

Referring to FIG. 6, certain types of indexing cables 200′ includemultiple branch cable sections 207A, 207B, 209A, 209B extendingoutwardly from at least one of the fanouts 211, 212. Each branch cablesection 207A, 207B, 209A, 209B is terminated by a respective branchconnector 208A, 208B, 210A, 210B. Each branch connector 208A, 208B,210A, 210B can be either a single fiber connector or a multiple fiberconnector. Each branch cable section 207A, 207B, 209A, 209B can includeone or more optical fibers 202. In certain examples, one branch cablesection 207A, 207B, 209A, 209B has a different number of cables thananother branch cable section 207A, 207B, 209A, 209B.

In some implementations, the number of first branch cable sections 207A,207B extending outwardly from the first fanout 211 is equal to thenumber of second branch cable sections 209A, 209B extending outwardlyfrom the second fanout 212. In other implementations, however, a totalnumber of fibers 202 included in the first branch cable sections 207A,207B is equal to the total number of fibers 202 included in the secondbranch cable sections 209A, 209B while the number of first branch cablesections 207A, 207B is different from the number of second branch cablesections 209A, 209B.

In certain implementations, the indexing cable 200′ that includesmultiple branch cable sections 207A, 207B, 209A, 209B also includesmultiple interface cable sections 203A, 203B, 205A, 205B as shown inFIG. 5.

In still other implementations, as noted above, one or more of thecables 200, 200′ does not include fanouts 211, 212. Rather, the opticalfibers 202 of the main cable section 201 are separated at locations thatare not enclosed. Rather, in certain types of cables 200, 200′, thefibers 202 of the main cable section 201 can be glued together while thefibers 202 of the interface cable sections and branch cable sections arenot glued together.

As shown in FIG. 7, certain types of fanout arrangements 211, 212include two or more fanouts. For example, each fanout arrangement 211,212 of the cable 200′ can include a first fanout 211A, 212A thatseparates the main cable section 201 into a branch set and an interfaceset. In implementations where the interface fibers are terminated atdifferent connectors 204A, 204B, 206A, 206B, a second fanout 211B, 212Bis disposed between the respective first fanout 211A, 212A and therespective interface connectors 204A, 204B, 206A, 206B to separate theinterface fibers into interface cable sections 203A, 203B, 205A, 205B.In implementations where the branch fibers are terminated at differentbranch connectors, a third fanout 211C, 212C is disposed between therespective first fanout 211A, 212A and the respective branch connectors208A, 208B, 210A, 210B to separate the branch fibers into branch cablesections 207A, 207B, 209A, 209B.

In some implementations, additional fanouts can be provided to furtherseparate out the interface fibers and/or the branch fibers. In otherimplementations, one or more of the fanouts can separate the fibers intothree or more sets. For example, in certain examples, a single fanout211, 212 can be provided at each side of the main cable section 201 toseparate out the interface fibers and branch fibers into any desirednumber of cable sections.

FIG. 8 illustrates another example indexing cable 300 including a maincable section 301 of multiple optical fibers 302. The first end of theindexing cable 300 includes a first interface cable section 303terminated by a first multi-fiber interface connector 304 and the secondend of the indexing cable 300 includes a second interface cable section305 terminated by a second multi-fiber interface connector 306. Thefirst end of the indexing cable 300 also includes a first branch cablesection 307 terminated at a first branch connector 308. The second endof the indexing cable 300 includes a second branch cable section 309terminated at a second branch connector 310.

In the example shown, the first interface cable section 303 and thefirst branch cable section 307 are separated from the main cable section301 at a first fanout arrangement 311; the second interface cablesection 305 and the second branch cable section 309 are separated fromthe main cable section 301 at a second fanout arrangement 312. As shownin FIG. 7, each fanout arrangement 311, 312 can include one or morefanouts. In other examples, however, the interface cable sections and/orbranch cable sections can be otherwise coupled (e.g., spliced) to themain cable section 301.

In accordance with some aspects of the disclosure, the indexing cablehas sufficient optical fibers to fill all sequential fiber positions ofthe first interface connector and at least one sequential fiber positionof the first branch connector. In the example shown, the indexing cable300 has sufficient optical fibers to fill all sequential fiber positionsof the first interface connector 304 and all sequential fiber positionsof the first branch connector 308. When the indexing cable 300 includesmore optical fibers than sequential positions at (all of) the interfaceconnector(s) 304, then the first branch connector 308 may function as anadditional input for the indexing cable 300.

The indexing cable 300 branches off a first number of optical fibers atthe second end of the cable. In certain implementations, the number ofoptical fibers 302 of the main cable section 301 over the total numberof sequential positions of (all of) the first interface connector(s) 304is no more than the first number of optical fibers that branch at thesecond end of the cable 300. Accordingly, when two or more indexingcables 300 are chained together, a sufficient number of optical fibersbranch at the second end of the first cable 300 to allow the secondinterface connector 306 to receive the second ends of the optical fibersextending from the first branch connector 304. Such animplementation—using the first branch cable section 307 as aninput-extends the number of cables that can be chained together by one.

In certain implementations, the second branch cable section 309 of thelast cable in the chain also can be utilized as an input for the cable.The signals provided to the second branch connector 310 of the lastcable 300 are carried over fibers having first ends indexed at the firstinterface connector 304 of the last cable 300 and thereby transitionedto the second-to-last cable in the chain.

Various modifications and alterations of this disclosure will becomeapparent to those skilled in the art without departing from the scopeand spirit of this disclosure, and it should be understood that thescope of this disclosure is not to be unduly limited to the illustratedexamples set forth herein.

What is claimed is:
 1. An indexing cable arrangement comprising: aplurality of optical fibers extending between opposite first ends andsecond ends; a plurality of first multi-fiber connectors terminating thefirst ends of at least some of the optical fibers, the first multi-fiberconnectors cooperating to define a total number of sequential firstinterface positions, wherein a total number of the at least some of theoptical fibers received at the first multi-fiber connectors is less thanthe total number of sequential first interface positions; a dropconnector coupled to the first end of at least one of the opticalfibers, wherein the at least one of the optical fibers is a drop fiber;and a second multi-fiber connector terminating the second ends ofmultiple ones of the optical fibers, the multiple ones of the opticalfibers being indexed between the second multi-fiber connector and thefirst multi-fiber connectors, wherein the second multi-fiber connectoris one of a plurality of second multi-fiber connectors, the secondmulti-fiber connectors cooperating to define a total number ofsequential second interface positions, wherein the total number ofsequential second interface positions is greater than a total number ofthe second ends of the optical fibers terminated at the secondmulti-fiber connectors.
 2. The indexing cable arrangement of claim 1,wherein the drop connector is a single-fiber connector.
 3. The indexingcable arrangement of claim 1, wherein the drop connector is amulti-fiber connector.
 4. The indexing cable arrangement of claim 3,wherein the multi-fiber drop connector defines fewer sequential fiberpositions than any of the first multi-fiber connectors.
 5. The indexingcable arrangement of claim 1, wherein each of the first multi-fiberconnectors defines a common number of the sequential first interfacepositions.
 6. The indexing cable arrangement of claim 1, furthercomprising a first fanout enclosing a location at which the opticalfibers are separated towards the first multi-fiber connectors.
 7. Theindexing cable arrangement of claim 6, further comprising a secondfanout enclosing a location at which the optical fibers are separatedinto interface fibers and the drop fiber, the interface fibers beingdirected to the first fanout, and the drop fiber being directed towardsthe first drop connector.
 8. The indexing cable arrangement of claim 1,wherein the optical fibers are separated towards the first multi-fiberconnectors at locations that are not enclosed.
 9. The indexing cablearrangement of claim 1, wherein the first drop connector is one of aplurality of first drop connectors that each terminate the first end ofa respective at least one of the optical fibers.
 10. The indexing cablearrangement of claim 1, further comprising a second drop connectorcoupled to the second end of at least one of the optical fibers.
 11. Theindexing cable arrangement of claim 10, wherein the second dropconnector is a single-fiber connector.
 12. The indexing cablearrangement of claim 10, wherein the second drop connector is amulti-fiber connector.
 13. The indexing cable arrangement of claim 10,wherein the second drop connector is one of a plurality of second dropconnectors that each terminate the second end of a respective at leastone of the optical fibers.
 14. The indexing cable arrangement of claim1, wherein each of the first multi-fiber connectors defines twelve ofthe sequential first interface positions.
 15. The indexing cablearrangement of claim 1, further comprising a terminal coupled to thedrop connector, the terminal including a body defining a plurality ofoutput ports.
 16. The indexing cable arrangement of claim 15, whereinthe terminal includes a single input connector disposed at an end of astub cable extending from the terminal.
 17. The indexing cablearrangement of claim 15, wherein the terminal houses an optical splitterthat outputs signals to at least some of the output ports of theterminal.
 18. The indexing cable arrangement of claim 17, wherein theterminal also defines a point-to-point connection.
 19. An indexing cablearrangement comprising: a plurality of optical fibers extending betweenopposite first ends and second ends; a plurality of first multi-fiberconnectors terminating the first ends of at least some of the opticalfibers, the first multi-fiber connectors cooperating to define a totalnumber of sequential first interface positions, wherein a total numberof the at least some of the optical fibers received at the firstmulti-fiber connectors is less than the total number of sequential firstinterface positions; a drop connector coupled to the first end of atleast one of the optical fibers, wherein the at least one of the opticalfibers is a drop fiber, the drop connector being a multi-fiberconnector, wherein the multi-fiber drop connector defines fewersequential fiber positions than any of the first multi-fiberconnectors.; and a second multi-fiber connector terminating the secondends of multiple ones of the optical fibers, the multiple ones of theoptical fibers being indexed between the second multi-fiber connectorand the first multi-fiber connectors.
 20. An indexing cable arrangementcomprising: a plurality of optical fibers extending between oppositefirst ends and second ends; a plurality of first multi-fiber connectorsterminating the first ends of at least some of the optical fibers, thefirst multi-fiber connectors cooperating to define a total number ofsequential first interface positions, wherein a total number of the atleast some of the optical fibers received at the first multi-fiberconnectors is less than the total number of sequential first interfacepositions; a drop connector coupled to the first end of at least one ofthe optical fibers, wherein the at least one of the optical fibers is adrop fiber; a second multi-fiber connector terminating the second endsof multiple ones of the optical fibers, the multiple ones of the opticalfibers being indexed between the second multi-fiber connector and thefirst multi-fiber connectors; a first fanout enclosing a location atwhich the optical fibers are separated towards the first multi-fiberconnectors; and a second fanout enclosing a location at which theoptical fibers are separated into interface fibers and the drop fiber,the interface fibers being directed to the first fanout, and the dropfiber being directed towards the first drop connector.
 21. An indexingcable arrangement comprising: a plurality of optical fibers extendingbetween opposite first ends and second ends; a plurality of firstmulti-fiber connectors terminating the first ends of at least some ofthe optical fibers, the first multi-fiber connectors cooperating todefine a total number of sequential first interface positions, wherein atotal number of the at least some of the optical fibers received at thefirst multi-fiber connectors is less than the total number of sequentialfirst interface positions; a drop connector coupled to the first end ofat least one of the optical fibers, wherein the at least one of theoptical fibers is a drop fiber; and a second multi-fiber connectorterminating the second ends of multiple ones of the optical fibers, themultiple ones of the optical fibers being indexed between the secondmulti-fiber connector and the first multi-fiber connectors; a terminalcoupled to the drop connector, the terminal including a body defining aplurality of output ports, wherein the terminal includes a single inputconnector disposed at an end of a stub cable extending from theterminal.
 22. An indexing cable arrangement comprising: a plurality ofoptical fibers extending between opposite first ends and second ends; aplurality of first multi-fiber connectors terminating the first ends ofat least some of the optical fibers, the first multi-fiber connectorscooperating to define a total number of sequential first interfacepositions, wherein a total number of the at least some of the opticalfibers received at the first multi-fiber connectors is less than thetotal number of sequential first interface positions; a drop connectorcoupled to the first end of at least one of the optical fibers, whereinthe at least one of the optical fibers is a drop fiber; and a secondmulti-fiber connector terminating the second ends of multiple ones ofthe optical fibers, the multiple ones of the optical fibers beingindexed between the second multi-fiber connector and the firstmulti-fiber connectors; a terminal coupled to the drop connector, theterminal including a body defining a plurality of output ports, whereinthe terminal houses an optical splitter that outputs signals to at leastsome of the output ports of the terminal.
 23. The indexing cablearrangement of claim 22, wherein the terminal also defines apoint-to-point connection.